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Homework Help: Question could someone help me

  1. Feb 27, 2009 #1
    hiii every body

    i have Home Work could some one help me to solve this Question" or give me the guide

    X, Y and Z are continuous random variables with joint density


    F(x,y,z)= {(3/32 x^2) y+[1/48(x+y)z For 0<x<2,
    0<y<1
    0<z<4
    elswhere =0


    1) find the marginal of x,y and z
    2)find E(x), E(y) and E(z)

     
  2. jcsd
  3. Feb 27, 2009 #2
    Someone shortly will tell you to post this in the homework section. To get the expectation of x integrate the x*F(x,y,z) over the domain. I forgot what the marginal is but looking at wikipedia it seems to be the distribution of a subset of the other random variables. So I presume to get the marginal in tems of x you integrate out the y and z variables.
     
  4. Feb 27, 2009 #3
    John Creighto thank u dear
     
  5. Feb 28, 2009 #4
    Apologize to forget to provide attempt part:

    1) find the marginal of x,y and z:
    i have try to integrate x and y together
    then the result be numbers with i reintegrate z to find the result
    i don't know if this way is true



    2)find E(x), E(y) and E(z)
    this question provide with 3 variable and i know only to solve by 2 variable

    someone help me please
     
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